Splash deflector



E. C. KIEKHAEFER Nov. 18, 1958 SPLASH DEF'LECTOR Filed April 20, 1955 2Sheets-Sheet 1 FML/L INVENTOR El MH? 1 MEKHAEFHP ATTORNEY 1 8 E.CI'KIEKHAEFER 2,360,594

SPLASH DEF'LECTOR Filed April 20, 1955 2 Sheets-Sheet 2 JIVVENTOR. [ZMHP6, KMKHAEfH? ATTORNEJ United States Patent SPLASH DEFLECTOR Elmer C.Kiekhaefer, Cedar-burg, Wis. Application April 20, 1955, Serial No.502,710

3 Claims. (Cl. 11517) This invention relates generally to outboardmotors, and more specifically to an improved splash deflector for anoutboard motor.

Outboard motors are generally provided with an exhaust discharge portdisposed at the lower end of the drive shaft housing above the waterlevel to eliminate any objectionable exhaust back pressure caused by thewater, particularly in reverse operation, which would tend to reduce theengine operating efficiency. The discharge of the exhaust into theatmosphere during engine operation produces undesirable noise andexhaust odors.

Furthermore, splash deflectors of the type embodied in Kiekhaefer PatentNo. 2,442,728 have been used to eliminate operational difliculty andunpleasant boating conditions arising as a result of water spray createdby the underwater movement of a part of the outboard motor. Althoughthis splash deflector has accomplished that result and has substantiallyeliminated the objectionable rooster tail developed at conventionaloperational speeds, it has not been so effective at high operationalspeeds of present outboard motors. This rooster tail may be defined asthe mass of water and water spray arising above the water surface andthrown backwardly in a direction opposite to the direction of the boatand motor. With the increased motor boat traffic on navigable waters,this rooster tail is objectionable with the water and spray therefromwetting the occupants and the interior of other nearby boats.

It is therefore an object of the present invention to eliminate theunpleasantness resulting from the rooster tail developed by present dayhigh speed outboard motors.

Another object of the invention is the provision of an improved splashdeflector for an outboard motor that muffles the exhaust noise producedthereby.

Another object of the invention is to provide an improved splashdeflector for an outboard motor wherein the forces developed by therooster tail against the deflector are used to raise the rear end of theboat.

Another object of the invention is to provide an improved splashdeflector for an outboard motor wherein a reduced pressure area isdeveloped at the exhaust port to reduce the exhaust back pressure of theengine.

Another object of the invention is the provision of an improved splashdeflector for an outboard motor for downwardly deflecting the roostertail developed by the outboard motor and boat, thereby shortening itseffective range.

Objects and advantages other than those set forth above will be apparentfrom the following description when read in connection with theaccompanying drawing, in which:

Fig. 1 is a side elevation view of an outboard motor secured to a boatand embodying the invention;

Fig. 2 is an enlarged fragmentary side elevation view partially insection showing the invention;

Fig. 3 is an enlarged fragmentary rear elevation view 2,850,594 PatentedNov. 18, 1958 of a portion of the drive shaft housing showing theinvention; and

Fig. 4 is a transverse section view taken on line 44 of Pig. 3.

As shown in the drawings, a preferred embodiment of this invention isillustrated and applied to an outboard motor 1 having a drive shafthousing 2, a cowl 3 mounted on the upper end of the drive shaft housing2 for enclosing an engine, not shown, and a gear housing 4 mounted tothe lower end of the drive shaft housing 2. Attachment means comprisinga clamp bracket 6 and a swivel bracket 7 is provided as shown in Fig. 1for attaching the outboard motor 1 pendantly to the transom 8 of a boat.

The drive shaft housing 2 and the gear housing 4 preferably separatejust beneath a horizontal anti-cavitation plate 9 which is castintegrally with the housing 2. The plate 9 is disposed above a propeller11 and serves to prevent cavitation.

The lower end of the drive shaft housing 2 has a rearwardly extendingshoe portion 12 which forms a rearwardly and downwardly extendingpassageway 13 leading to an exhaust discharge port 14.

An improved splash deflector 16 of applicants invention is mounted onthe shoe portion 12 of the drive shaft housing 2 above the water line.This deflector member 16 is preferably cast integrally with the driveshaft housing 2. The deflector 16 further extends circumferentially ofthe housing 2 in the form of a plate-like flange which may be ofsubstantially the same width and thickness throughout its entirety, andis shown preferably concave downwardly with the trailing edge 17 thereofextending rearwardly and downwardly slightly above and substantiallyparallel to the exhaust discharge port 14.

The splash deflector 16 should be positioned at a height above the waterline where it efficiently catches the upward spray and deflects itdownwardly. The actual location may vary depending upon the size of theoutboard motor 1 and boat, and should not be so high as to becomeineffective for the intended purposes. It is important, however, thatthe trailing edge 17 of the deflector 16 be positioned above andadjacent to the exhaust. port 14 and to extend rearwardly and downwardlysubstantially parallel to the direction of the exhaust flow therefrom.

In operation, the water and spray striking the splash deflector 16 formsa substantially solid sheet of water which is deflected downwardlydecreasing the size of the rooster tail and effectively covering orblanketing the exhaust port 14 to reduce the exhaust noise. The velocityof this sheet of water further develops a low pressure area at theexhaust port 14 reducing the exhaust back pressure of the engine. Thewater and spray striking the deflector 16 further imparts a force to thedeflector tending to raise the outboard motor 1 and rear portion of theboat out of the water. This is particularly beneficial at high speedsWhere the rear end of the boat tends to squat or settle down into thewater.

Although but one embodiment has been shown and described, it will beapparent to those skilled in. the art that various changes andmodifications of the invention may be made without departing from thespirit of the invention or from the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In an outboard motor having a substantially vertical drive shaftextending downwardly from the engine to a propeller shaft in the waterto drive the propeller, a housing for said shafts having a rearwardlyextending shoe portion, said shoe portion forming an exhaust passageextending rearwardly and downwardly to an exhaust port through which theexhaust is discharged rearwardly and downwardly, an anti-caviation platecarried by the lower end of said shoe portion substantially parallel tothe water line, and a splash deflector comprising a downwardly curvedflange of substantial width carried by said shoe above the water lineand spaced from said anti-cavitation plate, said splash deflector havinga trailing edge extending rearwardly and downwardly above said exhaustpassage and substantially parallel thereto to direct a substantiallysolid sheet of water in a rearward and downward direction substantiallyparallel to said exhaust discharge during forward movement of theoutboard motor whereby said exhaust discharge is effectively mulfied andthe exhaust back pressure of the engine reduced.

2. In an outboard motor having a drive shaft extending downwardly fromthe engine to a propeller shaft in the water to drive the propeller, ahousing for said shafts forming a passage leading to an exhaust portthrough which the engine exhaust is discharged, an anti-cavitation plateformed on said housing above said propeller and substantially parallelto the water line, and a splash deflector carried by said housing abovethe water line and spaced from said anti-cavitation plate, said splashdeflector being disposed above said exhaust port and forming a part ofthe exhaust passage leading to the exhaust port and having a trailingedge extending rearwardly and downwardly for directing a substantiallysolid sheet of water substantially parallel to the exhaust dischargeduring forward movement of the outboard motor whereby the exhaustdischarge is effectively rnuflled and the exhaust back pressure of theengine reduced.

3. In an outboard motor having a substantially vertical drive shaftextending downwardly from the engine to a propeller shaft in the waterto drive the propeller, a housing for said shafts having a rearwardlyextending shoe portion, said shoe portion forming an exhaust passageextending rearwardly and downwardly to an exhaust port through which theexhaust is discharged rearwardly and downwardly, an anti-cavitationplate carried by the lower end of said shoe portion substantiallyparallel to the water line, and a splash deflector comprising adownwardly curved flange of substantial width carried by said housingabove the water line and spaced from said anticavitation plate andmerged with the upper surface of said shoe portion to form a part ofsaid exhaust passage, said splash deflector having a trailing edgeextending rearwardly and downwardly above said exhaust passage andsubstantially parallel thereto to direct a substantially solid sheet ofwater in a rearward and downward direction substantially parallel tosaid exhaust discharge during forward movement of the outboardmotorwhereby said exhaust discharge effectively minded and the exh'austback pressure of the engine reduced.

References Cited in the file of this patent UNITED STATES PATENTS

